A manufacturing process for 3D additive matrix composite skin of unmanned aerial vehicle

Abstract

A manufacturing process for a 3D additive matrix composite skin of an unmanned aerial vehicle includes the following steps: Step 1: Building a fuselage jig; including setting a jig base, the jig base is flatly set on the ground, the upper surface of the jig base is provided with a jig slot, a fuselage structure is set on the jig slot, the jig slot and the fuselage structure are tangent, and the jig slot is controlled by a base support body set on the upper surface of the jig base to control the horizontal accuracy; Step 2: Assembling and fixing the fuselage jig; installing the unmanned aerial vehicle fuselage bulkhead on the unmanned aerial vehicle fuselage jig in a corresponding order, and placing the fuselage main beam on the unmanned aerial vehicle fuselage bulkhead component, and combining the unmanned aerial vehicle fuselage bulkhead component and the fuselage main beam into a whole by welding, riveting, gluing and other means; Step 3: Laying the matrix of the 3D additive skin on the outer side of the whole obtained in step 2, and laying the composite material on the matrix. The present invention realizes the rapid design and rapid manufacturing of large curvature structural parts.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles, and in particular to a manufacturing process for a 3D additive matrix composite skin of an unmanned aerial vehicle. Background Art

[0002] The existing UAV large curvature structure manufacturing is mainly based on mold and sheet metal processing manufacturing technology. These manufacturing technologies have the advantages of mature technology and strong applicability. However, for parts with large curvature such as fuselage and wings, mold and sheet metal processing and manufacturing technology also have disadvantages such as high production cost and long manufacturing cycle. Moreover, sheet metal manufacturing technology has difficulty in ensuring manufacturing accuracy and structural strength for large curvature parts.

[0003] In recent years, the development of 3D additive manufacturing technology has brought new ways to solve the manufacturing problems of large curvature structures. 3D additive manufacturing technology based on plastic polymer materials has the advantages of convenient modeling, strong adaptability, anti-oxidation, anti-corrosion, and short manufacturing cycle. However, it also has disadvantages such as insufficient structural strength of manufactured parts.

[0004] In order to give full play to the advantages of 3D additive manufacturing technology of plastic polymer materials in UAV manufacturing and overcome its shortcomings, the present invention proposes a recommended composite material manufacturing process scheme based on 3D additive manufacturing. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a 3D additive matrix composite skin manufacturing process for unmanned aerial vehicles. The purpose of the present invention is to overcome the shortcomings of insufficient structural strength of parts obtained by its manufacturing while retaining the advantages of 3D additive manufacturing technology of plastic resin polymer materials.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A process for manufacturing a 3D additive matrix composite skin of an unmanned aerial vehicle comprises the following steps;

[0008] Step 1: Build the fuselage frame;

[0009] The jig frame base 1 is arranged flatly on the ground, the jig frame base 1 is provided with a jig frame slot 2 on the upper surface, a fuselage structure 3 is arranged on the jig frame slot 2, the jig frame slot 2 and the fuselage structure 3 are tangent, and the jig frame slot 2 is controlled to have a horizontal precision by a base support body 4 arranged on the upper surface of the jig frame base 1;

[0010] Step 2: Assembling and fixing the body frame;

[0011] The unmanned aerial vehicle fuselage bulkhead 8 is installed on the unmanned aerial vehicle fuselage frame in the corresponding order defined by the fuselage frame, and the fuselage main beam 9 is placed on the unmanned aerial vehicle fuselage bulkhead 8 component. The manufacturing accuracy of the unmanned aerial vehicle fuselage bulkhead 8 component is ensured by positioning the unmanned aerial vehicle fuselage frame, and then the unmanned aerial vehicle fuselage bulkhead 8 component is combined with the fuselage main beam 9 into a whole by welding, riveting, gluing and other means;

[0012] Step 3: Using 3D additive skin as the base, laying glass fiber cloth or carbon cloth with resin as adhesive;

[0013] The matrix of the 3D additive skin is laid on the outer side of the whole obtained in step 2, and the composite material is laid on the matrix.

[0014] The preparation of the composite material in step 3 includes:

[0015] 1. First, prepare epoxy resin, mix type A and type B resin in a weight ratio of 3:10, and stir continuously for about 20 minutes until the mixture turns white;

[0016] 2. Apply the mixed epoxy resin to the surface of the substrate, and fit the fiberglass cloth tightly to the fuselage. At the same time, apply epoxy resin again on the fiberglass cloth to make it fit more closely to the fuselage, and eliminate the bubbles generated by the lock on the fuselage as much as possible.

[0017] 3. Place the uncured fuselage components coated with epoxy resin into a vacuum bag and evacuate the air to eliminate the bubbles on the surface;

[0018] 4. Place in a cool, ventilated place away from direct sunlight for 24 hours;

[0019] 5. Repeat steps 2 to 4 until the structural strength of the machine body meets the requirements.

[0020] 6. Apply putty to eliminate surface defects;

[0021] 7. Spray primer after 24 hours;

[0022] 8. Spray the surface paint several times until the surface quality meets the requirements.

[0023] The frame slot 2 is a supporting structure that is fixedly positioned with the slot base in the longitudinal direction and has an upper arc surface that is complementary to the fuselage bulkhead.

[0024] The positioning jig slot 7 is a slot-shaped fixing member for maintaining the jig slot 2 and the fuselage bulkhead stable.

[0025] The base support body 4 is used to ensure the horizontal accuracy of the fuselage during manufacturing. The component must remain horizontal during manufacturing and cannot move during the manufacturing process.

[0026] The base support body 4 has a fixed installation notch designed according to the fuselage structure; when the fixed groove 6 is fixedly installed in the installation notch in order, the manufacturing accuracy requirement of the longitudinal positioning of the UAV fuselage structure can be met. The fixed groove 6 is fixed with a positioning jig slot 7 for maintaining the longitudinal manufacturing accuracy of the UAV fuselage manufacturing. The contour shape of the positioning jig slot 7 is tangent to the shape of the UAV fuselage bulkhead 8 component, so that the fuselage bulkhead component 8 is placed and fixed on the jig slot 7.

[0027] The mold frame base 1 and the base support body 4 are rigidly fixed; the mold frame base 1 and the mold frame slot 2 are rigidly connected; the mold frame slot 2 and the fuselage structure 3 are placed through a fixing groove 6.

[0028] The fuselage bulkhead 8 and the fuselage main beam 9 are rigidly fixed.

[0029] Beneficial effects of the present invention:

[0030] The high manufacturing difficulty of large curvature structural parts is solved through the use of fuselage frame and 3D additive manufacturing technology, and the rapid design and rapid manufacturing of large curvature structural parts are realized;

[0031] By laying composite materials on 3D additive printed structural parts, the fragility of 3D additive printed structural parts is overcome, so that the fuselage obtained by applying this manufacturing process meets the requirements of accuracy and strength;

[0032] The transformation process has good economic efficiency and can save more than 70% of costs compared to drone mold processing and sheet metal processing and manufacturing processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the structure for the fuselage frame.

[0034] Figure 2 It is a side view of the fuselage structure 3.

[0035] Figure 3 It is a top view of the fuselage structure 3.

[0036] Figure 4 It is a schematic diagram of the fuselage frame structure.

[0037] Figure 5 A schematic diagram of the rack structure.

[0038] Figure 6 It is a schematic diagram of the overall rack structure.

[0039] Figure 7 This is a schematic diagram of the fuselage bulkhead. DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0041] like Figure 1-Figure 6 As shown: A manufacturing process for a 3D additive matrix composite skin of a UAV, comprising the following steps;

[0042] 1. Build the fuselage frame (key points: the frame base 1 is flat, the frame slot 2 and the fuselage structure 3 are tangent);

[0043] The UAV body frame includes a base support body 4 and a frame slot 2 fixed on a base 5 for positioning the UAV body structure 3.

[0044] The base support 4 is used to ensure the horizontal precision during the manufacturing process of the fuselage. Therefore, the component must be kept horizontal during manufacturing and cannot move during the manufacturing process.

[0045] The base support body 4 has a fixing groove 6 that meets the longitudinal manufacturing accuracy of the drone fuselage structure, and the fixing groove 6 is fixed with a positioning jig slot 7 for maintaining the longitudinal manufacturing accuracy of the drone fuselage manufacturing. The contour shape of the positioning jig slot 7 is tangent to the shape of the drone fuselage bulkhead 8 component, so that the fuselage bulkhead component 8 can be placed and fixed on the jig slot 7.

[0046] The application of the fuselage mold ensures the manufacturing accuracy of the UAV fuselage during the manufacturing process.

[0047] The jig base 1 and the base support 4 are rigidly fixed; the jig base 1 and the jig slot 2 are rigidly connected; the jig slot 2 and the fuselage structure 3 are arranged via a fixing groove 6 .

[0048] 2. Assembly and fixation of the fuselage frame;

[0049] The drone fuselage bulkhead 8 components are installed on the drone fuselage frame in the corresponding order, and the fuselage main beam 9 is placed on the drone fuselage bulkhead 8 components. The manufacturing accuracy of the drone fuselage bulkhead 8 components is ensured by positioning the drone fuselage frame. Then, the drone fuselage bulkhead 8 components and the fuselage main beam 9 are combined into a whole by welding, riveting, gluing, etc.

[0050] The fuselage bulkhead 8 and the fuselage main beam 9 are rigidly fixed.

[0051] 3. 3D additive skin structure and fuselage assembly;

[0052] The 3D additive printing structural parts of the drone body can be manufactured in several parts according to the requirements of structural strength, maintenance convenience, etc. The fuselage parts manufactured in blocks have a clamping groove 10 inside that is combined with the fuselage bulkhead part 8, which facilitates the fixed installation of the 3D additive printing structural parts and the fuselage bulkhead part 8. The specific installation method can be riveting, bonding, etc. Through the connection of the fuselage bulkhead 8 parts, the 3D additive printing structural parts manufactured in blocks form a complete fuselage.

[0053] The 3D additive skin structure and the fuselage are semi-rigidly fixed using tough epoxy resin.

[0054] 4. Use 3D additive skin as the matrix and resin as the adhesive to lay glass fiber cloth or carbon cloth;

[0055] The fuselage manufactured by the first two steps can ensure the required manufacturing accuracy, but there is a problem of insufficient structural strength. In order to solve this problem, the present invention adopts a 3D additively printed structural part as a substrate and lays a composite skin thereon to improve the structural strength of the fuselage.

[0056] Composite material manufacturing mainly includes adhesives and fiber layers (glass fiber cloth, carbon cloth, etc.). The following takes epoxy resin as an adhesive and glass fiber cloth as a fiber layer as an example to illustrate the specific manufacturing process.

[0057] First, prepare epoxy resin by mixing type A and type B resin in a weight ratio of 3:10, and stir continuously for about 20 minutes until the mixture turns white.

[0058] The second step is to apply the mixed epoxy resin to the surface of the fuselage and fit the fiberglass cloth tightly to the fuselage. At the same time, apply epoxy resin again on the fiberglass cloth to make it fit more closely to the fuselage and eliminate the bubbles generated by the lock on the fuselage as much as possible.

[0059] 5. Put it into a vacuum bag and remove air bubbles on the surface;

[0060] 6. Place in a cool, ventilated place away from direct sunlight for 24 hours;

[0061] 7. Repeat steps 4 to 6 until the structural strength of the machine body meets the requirements.

[0062] 8. Apply putty to eliminate surface defects;

[0063] 9. Spray primer after 24 hours;

[0064] 10. Spray the surface paint several times until the surface quality meets the requirements.

[0065] like Figure 7As shown: There are seven parts in the fuselage bulkhead, in the order from the front to the back of the nose. The holes on the bulkhead are the limit holes of the longitudinal beams of the UAV fuselage, and the two cross beams are arranged along bulkheads 5 and 6 respectively. At the same time, bulkheads 5 and 6 extend toward the fuselage to connect and maintain the 3D additive printed skin of the fuselage. The opening in the middle of the bulkhead is the central equipment compartment of the UAV fuselage. Bulkhead 7 is the rear end bulkhead of the fuselage, and the limit holes on it are used to fix the engine base and the engine.

Claims

1. A process for manufacturing a 3D additive matrix composite skin for an unmanned aerial vehicle, characterized in that: The steps include: Step 1: Build the fuselage frame; The invention comprises a jig frame base (1), the jig frame base (1) being arranged flatly on the ground, the jig frame base (1) being arranged with a jig frame slot (2) on the upper surface, a fuselage structure (3) being arranged on the jig frame slot (2), the jig frame slot (2) and the fuselage structure (3) being tangent to each other, and the jig frame slot (2) being arranged with a base support body (4) on the upper surface of the jig frame base (1) to control the precision of the horizontal direction; Step 2: Assembling and fixing the body frame; The drone fuselage bulkhead (8) is placed on the drone fuselage frame in the corresponding order defined by the fuselage frame, and the fuselage main beam (9) is placed on the drone fuselage bulkhead (8). The manufacturing accuracy of the drone fuselage bulkhead (8) is ensured by positioning the drone fuselage frame, and then the drone fuselage bulkhead (8) and the fuselage main beam (9) are combined into a whole by welding, riveting, and gluing. Step 3: Using 3D additive skin as the base and resin as the adhesive to lay glass fiber cloth or carbon cloth; Laying a matrix of the 3D additive skin on the outer side of the whole obtained in step 2, and laying a composite material on the matrix; The preparation of the composite material in step 3 includes:

1. First, prepare epoxy resin, mix type A and type B resin in a weight ratio of 3:10, and stir continuously for about 20 minutes until the mixture turns white; 2. Apply the mixed epoxy resin to the surface of the substrate, and fit the fiberglass cloth tightly to the fuselage. At the same time, apply epoxy resin again on the fiberglass cloth to make the fiberglass cloth and the fuselage fit more closely, and eliminate the bubbles generated on the fuselage as much as possible.

3. Place the uncured fuselage components coated with epoxy resin into a vacuum bag and evacuate the air to eliminate surface bubbles; 4. Place in a cool, ventilated place away from direct sunlight for 24 hours; 5. Repeat steps 2 to 4 until the structural strength of the machine body meets the requirements; 6. Apply putty to eliminate surface defects; 7. Spray primer after 24 hours; 8. Spray the surface paint several times until the surface quality meets the requirements.

2. The manufacturing process of a 3D additive matrix composite skin of an unmanned aerial vehicle according to claim 1, characterized in that: The frame slot (2) is a supporting structure that is fixedly positioned with the slot base in the longitudinal direction and has an upper curved surface that complements the fuselage bulkhead.

3. The manufacturing process of a 3D additive matrix composite skin of an unmanned aerial vehicle according to claim 1 is characterized in that: The base support body (4) is used to ensure the accuracy of the horizontal direction during the manufacturing process of the fuselage. The base support body (4) must be kept horizontal during the manufacturing process and cannot move during the manufacturing process.

4. The manufacturing process of a 3D additive matrix composite skin of an unmanned aerial vehicle according to claim 1, characterized in that: The base support body (4) is provided with a fixing groove (6) with longitudinal manufacturing accuracy, and a positioning frame card slot (7) used for manufacturing the drone fuselage to maintain longitudinal manufacturing accuracy is fixed on the fixing groove (6), and the contour shape of the positioning frame card slot (7) is tangent to the shape of the drone fuselage bulkhead (8), so that the drone fuselage bulkhead (8) is placed and fixed in a close fit on the positioning frame card slot (7).

5. The manufacturing process of the 3D additive matrix composite skin of a UAV according to claim 4 is characterized in that: The positioning jig slot (7) is a slot-shaped fixing part for maintaining the jig slot (2) and the fuselage bulkhead stable.

6. The manufacturing process of a 3D additive matrix composite skin of an unmanned aerial vehicle according to claim 1, characterized in that: The mold frame base (1) and the base support body (4) are rigidly fixed; the mold frame base (1) and the mold frame slot (2) are rigidly connected; and the mold frame slot (2) and the fuselage structure (3) are arranged via a fixing groove (6).

7. The manufacturing process of a 3D additive matrix composite skin of a UAV according to claim 1, characterized in that: The UAV fuselage bulkhead (8) and the fuselage main beam (9) are rigidly fixed.

Images